Method and apparatus for endoscopic grafting

ABSTRACT

Method and apparatus for reconstructing target tissue by grafting uses a stabilizing balloon cannula having an endoscope for visualizing the placement of the graft during the procedure. The method and apparatus advances a sheathed graft to the target tissue, releases the graft at the target site, occludes the target tissue, deploys a graft stabilizing catheter, dissects a cavity outside the target tissue site, maintains the dissection site, and then secures the graft to the target tissue. Alternatively, the method and apparatus creates a cavity extending to the target tissue using an everting balloon cannula with an endoscope, maintains the dissection site, introduces the graft to the target site via the dissection site, and then secures the graft to the target tissue.

This is a divisional of application Ser. No. 08/290,361 filed on Aug.15, 1994 now U.S. Pat. No. 5,571,172.

BACKGROUND OF THE INVENTION

1. Related Applications

This application is related to U.S. patent application Ser. No.08/269,666, entitled "Everting Cannula Apparatus and Method", filed 1Jul., 1994, the subject matter of which is incorporated herein by thisreference.

2. Field of the Invention

The present invention relates generally to a method for grafting tissueat a target site, and specifically relates to endoscopic aortofemoralbypass grafting.

DESCRIPTION OF BACKGROUND ART

Prosthetic graft insertion from the abdominal aorta to the femoralvessels in the groin has become the standard method of direct surgicalrepair for aortoiliac occlusive disease over the past two decades. See,Brewster, D. C., "Aortoiliac, Aortofemoral, and IliofemoralArteriosclerotic Occlusive Disease", in Haimovici, H.(ed.), VascularSurgery: Principles and Technique (Appleton & Lange, 1989)!. The methodis used in over 90% of such patients by most vascular surgeons. Presenttechniques for performing aortic reconstruction include open surgicalbypass via an abdominal approach, a retroperitoneal approach, orinfrequently, an endovascular approach, using a stented graft introducedthrough an incision in the femoral artery.

The open surgical approaches, either transabdominal or retroperitoneal,require large abdominal or flank incisions, approximately 20-30 cm inlength for exposure and manipulation of the aorta. In this procedure,the aorta is cross-clamped for a period of time, which may increase thepotential of ischemia to the kidneys or bowel. The postoperativerecovery period is prolonged as a result of such trauma to the patient'sorgans and system.

Laparoscopic approaches, using small incisions and rigid endoscopes tovisualize inside the abdomen for the aortic anastomosis may be used andare known in the art. The laparoscopic technique requires multipleincisions, for example 4-5 incisions varying between 1-4 cm in lengtheach. In addition, the laparoscopic technique requires multipleretractors to control and displace the bowel to enable access to theaorta. Aortic cross-clamping is required, and suturing the aorticanastomosis is difficult, increasing the cross-clamp time. The operativetime is prolonged using this approach due to the difficulties associatedwith bowel retraction.

The most recent technique is the endovascular approach, which does notrequire abdominal incisions, since the graft is introduced via a groinincision and a femoral artery cutdown. Aortic cross-clamping is notrequired with this approach. The stented grafts used in practicing thistechnique are large in diameter, and graft introduction is only possiblein patients with large, undiseased femoral arteries. Metal stents oranchors used to secure the proximal aortic end of the graft may not holdthe graft properly, leading to graft migration. Alternatively, the metalstents or anchors may work their way through the wall of the aorta,causing aortic perforation and death.

Thus, there remains a need for a less invasive technique for performingaortofemoral bypass grafting that decreases the trauma to a patient'ssystem and organs and the concomitant recovery time.

SUMMARY OF THE INVENTION

In accordance with the present invention, aortofemoral bypass graftingis performed using a specialized dissecting balloon cannula having anendoscope for visualizing the placement of the graft during theprocedure.

In one embodiment of the present invention, a sheathed graft is advancedvia a femoral cutdown. Once the graft is released from the sheath at thetarget location, such as at the aorta, a stabilizing system is advancedto the graft site. By separating the steps of graft insertion and graftstabilization at the target site, e.g., against the inside of the aorta,conventional insertion of a large diameter system through the femoralartery is avoided, and the technique of the present invention becomesapplicable to a larger group of patients. Specifically, thecontralateral femoral graft limb is pulled into position using a priorplaced guidewire, and this avoids the difficulty commonly associatedwith the conventional technique of catching free ends of intravascularcatheters using basket snares, and the like.

Once the graft is in position, a retroperitoneal space is createdsurrounding the aorta, using an everting dissection cannula. The spaceis maintained via retroperitoneal insufflation, or via a gaslesstechnique incorporating mechanical retraction or structural balloonsupport. The aorta is isolated, and the proximal anastomosis isperformed from the outside of the aorta, using interrupted sutureanchors or a running suture. The aorta may be cross-clamped during theperformance of the anastomosis, or an occlusion balloon may be advancedfrom the femoral access site.

In an alternative embodiment of the present invention, an evertingballoon cannula is used to dissect a passageway from the infrarenal areato below the aortic bifurcation. A mechanical retraction system or astructural balloon then is used to maintain the retroperitoneal workingcavity. Alternatively, retroperitoneal insufflation may be used tomaintain the cavity.

A visualization cannula then is used from, e.g., bilateral groinincisions, to form tunnels leading to the retroperitoneal space, forpassage of femoral graft limbs. The proximal aortic anastomosis isperformed while the aorta is cross-clamped. The femoral limbs of thegraft are pulled down through the tunnels and the distal anastomoses areperformed via the bilateral groin incisions. This total retroperitonealapproach is applicable to patients with abdominal aortic aneurysms orpatients with atherosclerotic aortic occlusive disease.

A double-lumen balloon cannula may be used to perform the bluntdissection of an elongate, non-spherical cavity under visual control.Such a cannula includes a first lumen that accommodates an endoscopetherewithin, and a second lumen having an inverted, nonelastomeric,transparent balloon contained therewithin. The balloon is attached tothe outer surface of the distal end of the cannula. Thus, as the balloonis being everted, it extends over the distal end of the first lumen topermit passage therethrough of the endoscope for visualization of thetissue adjacent the balloon.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of one embodiment of the method of the presentinvention.

FIG. 2A shows a longitudinal cross- section view of an embodiment of asheathed graft that may be used in practicing the present method.

FIG. 2B shows a side elevation view of the sheathed graft of FIG. 2A.

FIG. 2C shows a side perspective view of a graft emerging from thesheath shown in FIGS. 2A and 2B in accordance with the presentinvention.

FIG. 3 is a flowchart of an alternative embodiment of the method of thepresent invention, wherein the graft is an aortofemoral graft.

FIG. 4 is a side elevation view of an aortic balloon occlusion catheterthat may be used in practicing the present invention.

FIG. 5A is a side partial cut-away view of a graft stabilizing catheterthat may be used in practicing the present invention.

FIG. 5B is a side cut-away view of the graft stabilizing catheter ofFIG. 5A with the sheath drawn back away from the extensions and balloon.

FIG. 5C is a side perspective view of the graft stabilizing catheter ofFIGS. 5A and 5B in its fully deployed state.

FIG. 6 is a flowchart illustrating an alternative embodiment of themethod of the present invention.

FIGS. 7A-7G are top cut-away views of the aorta, illustrating theintroduction and deployment of the graft therewithin in accordance withthe method of the present invention.

FIG. 8A shows a side elevation view of an embodiment of an evertingballoon cannula that may be used in practicing the present method.

FIG. 8B shows in cross-section the cannula of FIG. 8A taken along linesB--B of that figure.

FIG. 8C shows the cannula of FIG. 8A in longitudinal cross-section,showing the balloon in its inactive, inverted position within theballoon lumen.

FIG. 8D is a longitudinal cross-section of the cannula of FIG. 8C,showing the balloon in its active, everted position.

FIG. 9 is a cross-sectional view of a retroperitoneal cavity with aballoon retractor and a fan retractor in position in accordance with thepresent invention.

FIG. 10A is a top plan view of a laparoscopic oval balloon retractorthat may be used in practicing the present invention.

FIG. 10B is a front plan view of the oval balloon of the retractor shownin FIG. 10A.

FIG. 11 is a flowchart of an alternative embodiment of the method ofFIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention includes an improved method for introducing agraft into a body passageway and apparatus used in practicing themethod. In a preferred embodiment, and as described below, the presentinvention is a method for introducing an aortofemoral bypass graft intothe aorta.

A flowchart of one embodiment of the present invention is shown inFIG. 1. In that embodiment, an aortofemoral graft is placed via afemoral artery cutdown 100. Preferably, and as shown in FIGS. 2A through2C, the graft 200 is encased in a perforated sheath 202 to form asheathed graft 210.

The graft 200 may be manufactured from tissue, plastics, textiles, andother materials that can be sterilized and that retain shape.Preferably, the graft 200 is formed from a synthetic material such aspolytetrafluoroethylene (PTFE, also known as Teflon), or a textile suchas Dacron. Alternatively, the graft may be a tissue, such as umbilicalvein. PTFE is commercially available from W. L. Gore & Associates, Inc.,Naperville, Ill., and the textile is commercially available from MeadoxMedicals, Inc., Oakland, N.J. The graft may be made from any suitablematerials having good suturability, and which are non-thrombogenic. Thegraft material preferably also is non-kinking and does not dilate overtime. Preferably, the graft 200 is a bifurcated graft constructed ofDacron or Teflon (PTFE or polytetrafluoroethylene), with the proximalhalf of the graft 200 of approximately 16 mm in diameter, and thedistal, femoral limbs of the graft 200 approximately 8 mm in diameter.The sheath 202 may be manufactured from a bioinert plastic,polyethylene, polyurethane, polyvinyl chloride (PVC), polyimide plastic,and the like. In a preferred embodiment, the sheath 202 has alongitudinal perforation added using a cutting die. The sheath 202 mayalso have a transverse slit approximately halfway along its length.

The femoral limb with an attached loop 204 may be folded in half, andfolded back onto the proximal part of the graft 200 at the bifurcation.One half of the sheath 202 encloses the large diameter portion of thegraft 200 proximal to the bifurcation, plus the folded femoral graftlimb; the other half of the sheath 202 encloses the other femoral graftlimb, which remains unfolded. The sheath 202 may be approximately 40-60cm in length.

The distal end of one femoral limb of the graft 200 has an attached loop204 that protrudes from an opening in the middle of the sheath 202. Thisloop 204 is threaded along the length of a previously placed guidewire(not shown) which has been advanced from the first femoral arteryincision (arteriotomy), across the aortic bifurcation, and down thecontralateral femoral artery, to exit the second femoral arteriotomy.After the graft 200 has been advanced into position in the aorta andreleased, a bead (not shown) may be crimped onto the guidewireimmediately outside the first femoral arteriotomy. The guidewire may bepulled out of the second arteriotomy, with the crimped bead catching theloop 204 and pulling the contralateral femoral limb of the graft 200down the contralateral femoral artery and out of the second femoralarteriotomy.

An enclosed chamber 206 runs the length of the sheath 202. When thischamber 206 is inflated via an attached inflation port 208, the sheath202 splits open along the perforation to release the graft 200. Thesheath 202 than may be removed from the cavity, or left in place ifmanufactured from a resorbable material, such as polyglycolic acid.Thus, the present sheathed graft 210 obviates the wire stents or hooksof conventional total endovascular placed grafts. In addition, theinitial diameter of the sheathed graft 210 is smaller than conventionalendovascular graft inserts since no such stents and hooks are requiredon the outer surface of the graft of the present invention.

Continuing the present method, the sheathed graft 210 is advanced 101 ina retrograde fashion, from the femoral artery through the iliac arteryinto the aorta, until it is in position at the target location,preferably against the side of the aorta. The graft 200 then is released102 from the sheath 202 at the target site, in the manner describedabove. Specifically, the sheath chamber 206 is inflated with saline orother appropriate fluid until the sheath 202 splits open along the lineof perforation to release the graft 200.

The graft 200 is anchored 103 at the target site by suturing theproximal end of the graft 200. In the embodiment wherein the graft 200is an aortofemoral graft, the anchoring 103 step is achieved by suturingvia a retroperitoneal laparoscopic approach. Interrupted sutures may beplaced to anchor 103 the proximal end of the graft 200.

Once the graft 200 is positioned, the dissection site is maintained 106.This may be achieved in several conventional ways, including using astructural balloon, insufflation, or mechanical structures. In apreferred embodiment, and as outlined in the flowchart shown in FIG. 3,once the graft 200 is anchored 103, the aorta may be occluded 104 byadvancing an aortic balloon occlusion catheter 400 proximal to the graft200 and by inflating the balloon to occlude the aorta. If possible, thisocclusion is performed just distal to the origin of the renal arteries,to preserve perfusion to the kidneys. An exemplary occlusion catheter400 is shown in FIG. 4.

As shown in FIG. 4, the occlusion catheter 400 may be constructed of ahollow shaft 402 or tube with an elastomeric balloon 404 at one end ofthe shaft 402 and an inflation port 406 at the other end of the shaft402. This catheter 400 may be any conventional occluding cathetergenerally commercially available. In using the illustrated catheter 400,the shaft 402 is introduced to the target site with the balloon 404collapsed within or tightly surrounding the hollow shaft 402. Oncepositioned, fluid is introduced via the port 406 into the shaft 402 toinflate the balloon 404.

Once the aorta is occluded 104, the graft stabilizing catheter 500, orother stabilizing catheter system may be deployed 105. Such a catheter500 is advanced to the proximal end of the graft and deployed to pressthe graft 200 against the aortic wall. An exemplary graft stabilizingcatheter 500 of the type that may be used in practicing the presentmethod is shown in FIGS. 5A through 5C.

In that illustrated embodiment, the catheter 500 includes an outersheath 502 which houses a balloon 504, shown in FIG. 5C in its inflatedform. The sheath 502 covers the balloon and several extensions 510 forease of insertion and advancement through the graft 200. A ballooninflation port 506 is included near the remote end of the catheter 500in fluid-tight connection to the balloon 504 to facilitate the remoteinflation of the balloon 504 to assist in maintaining 106 the dissectionsite.

In a preferred embodiment, the catheter 500 includes a fiberopticendoscope 508 which extends, as shown in FIG. 5C, into the balloon 504when the balloon 504 is in its deployed, inflated form. Using theendoscope 508, a user may visualize the placement of the catheter 500 atthe proximal end of the graft 200, for example, as illustrated in FIG.7G. In the illustrated embodiment, the catheter 500 includes anirrigation port 512, for flushing the catheter 500 with, e.g., saline.Flushing the catheter 500 with saline clears the graft 200 of blood toallow visualization through the scope 508.

In addition, the illustrated catheter 500 may include severalfinger-like resilient extensions 510, which splay outward when theballoon 504 is inflated. The extensions 510 are deployed by withdrawingthe sheath 502 away from the enclosed extensions 510 which then springoutwardly into a fan-like deployed shape upon inflation of balloon 504,as shown in FIG. 5C. Once deployed, the extensions 510 are visibleoutside the aorta, assisted by translluminational provided by afiberoptic light source integral with the endoscope 508.

The extensions 510 may be formed of a stainless steel wire, anickel-titanium wire, or wire coated with a bioinert coating material,such as polytetrafluoroethylene (Teflon), polyethylene, polyvinylchloride, or silicone rubber. The balloon may be made of polyethylene,polyethylene terephthalate (PET), polyvinyl chloride, or other generallyinelastic materials. The extensions 510 may be attached to the catheter500, inserted into multiple, symmetrically spaced lumens placed aroundthe central balloon inflation lumen, or they may be bonded to theoutside of the catheter 500. The extensions 510 also may be attached tothe outer surface of the balloon 504 in a symmetrical fashion,approximately at the midpoint along the length of the extension 510.Thus, each extension 510 is stabilized at two points, at the proximalend and at its midportion, allowing the distal end of the extension topivot outward upon inflation of balloon 504.

Once the graft 200 is properly positioned and maintained in the aorta orat the target site, the proximal end of the graft is sutured 107 to thetarget site, or into the aorta. Placement of interrupted suturespreferably is accomplished from the outside of the aorta, via theretroperitoneal route. The fiberoptic scope 508 in the stabilizingcatheter 500 allows evaluation of suture placement from the inside ofthe graft 200.

The aortofemoral graft 200 typically includes two femoral limbs. If thegraft 200 is advanced via the right femoral artery, as illustrated inFIG. 7A, the left limb of the graft 200 must be pulled 108 down the leftiliac and femoral arteries. This may be accomplished by the priorintroduction of a catheter 700, including a guidewire 702, via the rightfemoral artery, which then passes over the aortic bifurcation and downthe left femoral artery, as shown in FIG. 7B.

The distal end of the left femoral limb of the aortofemoral graft mayinclude a small loop 704 that is threaded over the guidewire 702, as thegraft 200 is advanced into the aorta. A small bead 706 may be crimpedonto the guidewire 702 so that passage of the guidewire 702 out of anincision in the left femoral artery facilitates manually pulling theleft femoral limb of the graft 200 into the left femoral artery and outthe incision, following the bead 706.

The present method is described further with reference to FIGS. 7D and7G. As illustrated, once the sheathed graft 210 is in position, thesheath 202 is split open at the perforation to release the graft 200into position in the aorta 120. The aortic occlusion balloon 400 then isintroduced through the positioned graft, as shown in FIG. 7E, and theballoon 402 is distended to occlude 104 the aorta above the graft site.

The stabilizing catheter 500 then is introduced into the graft 200, asshown in FIG. 7F, the sheath 502 retracted, and the balloon SW4inflated, to deploy the extensions 510 within the graft 200, as shown inFIG. 7G. The graft 200 then may be sutured 107 into place. As a finalstep, the femoral limbs of the graft 200 are pulled 108 through theremaining arteries, as shown in FIGS. 7D, 7E, 7F, and 7G, for suturingthe graft into place.

In another embodiment of the present invention, and as shown in theflowchart of FIG. 6, a blunt dissection cannula 800, is used to bluntlydissect 600 a cavity extending from an initial incision to the targetgraft site. In a preferred embodiment, a 15 mm incision is made in theleft flank, approximately 2 cm above the iliac crest in the anterioraxillary line. Separate groin incisions may be made to isolate thecommon femoral artery on both sides.

A blunt dissection cannula 800 that may be used in practicing thepresent invention is shown in FIGS. 8A through 8D. In that illustratedembodiment, the cannula 800 includes an inverted inelastic balloon 806folded within a first lumen, and an endoscope 810 within a second lumen.Once the cannula 800 is positioned, the balloon 806 is inflated via apressure fitting 803 to extend the balloon 806 from the end of thecannula, as shown in FIG. 8D and bluntly dissect an elongated tissueplane. The endoscope 810 may be inserted through end 805 that includes agas-tight sliding seal to facilitate visualizing the dissection processfrom within the inflated balloon 806 as the cannula 800 is advanced.

Blunt finger dissection 600 and muscle spreading result in a plane downto the peritoneum. An everting balloon cannula 800, preferably of thetype shown in FIGS. 8A through 8D, then is introduced 601 into theincision and pointed inferiority. The balloon 806 of the evertingcannula 800 is inflated 602 and the balloon 806 everts 603 to create acavity along the target site, e.g., the aorta. The balloon 806 then isdeflated and the cannula 800 removed prior to introduction of a trocar.After dissection, a blunt tip trocar with a sealing balloon and amovable foam cuff may be used to seal 604 the entrance tract and allowmaintenance 605 of the dissected space for subsequent instrumentinsertion and manipulation via insulation. A conventional blunt tiptrocar may be used, such as ones commercially available from OriginMedsystems, Inc. (Menlo Park, Calif.).

Mechanical support may allow maintenance 605 of the dissected spacewithout the need for a blunt tip trocar or insufflation. The mechanicalsupport may include a fan retractor 902, attached to a mechanical arm(not shown) used in conjunction with a separate small mechanical orballoon retractor 904, as shown in FIG. 9. In that illustratedembodiment, the fan retractor 902 is introduced into the retroperitonealcavity 906 then activated to maintain that cavity 906 in an expandedmanner. The balloon retractor 904 is introduced into the cavity 906 andused to apply pressure against the peritoneum 908 and thus against thebowel 910.

FIG. 10A shows a top plan view of an exemplary laparoscopic oval balloonretractor 904 of the type that may be used in practicing the presentinvention. As shown, the retractor 904 includes a substantially rigid,tubular shaft 1002, with an attached handle 1004 at one end and aflexible, inflated, oval balloon 1006 at the other end. The balloon 1006is shown in front plan view in FIG. 10B.

Alternatively, the dissecting balloon cannula 800 may be a structuraltype balloon with operating windows for access to the infrarenal aortaand the aortic bifurcation. Thus, the dissected space may be maintained605 in a manner similar to that described above.

Once the dissection site is established, the graft 200 may be secured606 in place, preferably by suturing the graft 200. In a preferredembodiment, and as shown in the flowchart of FIG. 11, the proximal endof the graft may be sutured 606 into the aorta and may be performed viathe retroperitoneal cavity. Tunnels then may be dissected 607 from thegroin incisions to the retroperitoneal cavity, and the femoral limbs ofthe graft pulled 608 through the dissected tunnels. In that embodiment,the distal anastomoses are performed via the groin incisions.

FIGS. 8A-8C show an embodiment of the dissection cannula 800 of thepresent invention. This illustrated cannula is described in detail inU.S. patent application No. 08/269,666, filed 1 Jul., 1994, and entitled"Everting Cannula Apparatus and Method", which application isincorporated by reference herein in its entirety.

The cannula 800 includes an elongated, tubular member 802 having onelumen 804 for containing an inverted balloon 806 and another lumen 808for supporting an endoscope 810 therein as shown in cross-section inFIGS. 8B and 8C. In other embodiments, the cannula 800 may includeadditional lumens, such as a lumen through which a guide-wire may bepassed.

An elliptical, nonelastic balloon 806 is inverted into lumen 804 priorto introduction of the cannula 800 to the dissection site. The balloon806 is attached to the outer edges of the distal end of the cannula 800to ensure that the balloon 806, when in its everted, inflated state(shown in FIG. 8D), extends outwardly from the distal end of the cannula800 and completely encloses that end of the cannula 800.

As shown in FIG. 8A, the proximal end of the cannula 800 preferably issealed. In addition, a conventional sliding pressure seal 801 isprovided around an endoscope inserted into the lumen 808. This enables apositive pressure to be established within the balloon lumen 804 uponactivation of the cannula 800 at the dissection site. When a positivepressure is established within that lumen 804, the inverted balloonshown in FIG. 8C becomes everted and extended, as shown in FIG. 8D. Thepositive pressure necessary to evert the balloon 806 may be produced byair or fluid introduced into the lumen 804 via a pressure fitting 803 atthe proximal end of the cannula 800 which communicates with the balloonlumen 804 to receive a source of air or fluid under pressure, forexample from a manually operable syringe.

The illustrated cannula 800 also includes a second lumen 808 for housingan endoscope 810 therewithin. The size of the lumen 808 depends on thediameter of the endoscope 810 to be introduced therewithin. A preferredendoscope 810 having a tubular diameter of about 10 mm is commerciallyavailable from Karl Storz Endoscopy America, Inc.

What is claimed is:
 1. A method for reconstruction of target tissue,using a sheathed graft encased in a casing and a stabilizing catheterhaving a plurality of selectively deployable extensions at one endthereof, the method comprising the steps of:introducing the sheathedgraft through an introduction site to position the sheathed graft at aproximal part of the target tissue; releasing the graft from the casing;deploying the extensions of the stabilizing catheter at a proximal partof the graft to press the graft adjacent the target tissue to stabilizethe graft at the target tissue; securing the graft to the target tissue;and removing the extensions of the stabilizing catheter from the graftsecured to the target tissue.
 2. The method of claim 1, wherein thetarget tissue comprises aortic tissue, and the method furthercomprises:inserting a balloon occlusion catheter, having a selectivelyinflatable balloon, through the graft; and then selectively inflatingthe balloon to occlude the aorta prior to deploying the extensions ofthe stabilizing catheter.
 3. The method of claim 2, wherein positioningthe sheathed graft comprises advancing the graft into position at theaortic tissue via one femoral artery.
 4. The method of claim 3, furthercomprising, after positioning the graft, pulling a limb of the graftdown iliac arteries and femoral arteries opposite the introduction site.5. The method of claim 4, wherein the graft further comprises a loopelement attached thereto, the method further comprising the step of,prior to pulling the limb of the graft, introducing a guidewire throughthe loop into the femoral arteries and the iliac arteries.
 6. The methodof claim 1, wherein the step of securing the graft comprises suturingthe graft to the target tissue.
 7. The method according to claim 1 inwhich the sheathed graft includes an inelastic perforated casing and aballoon therein for selective expansion within the casing in response topressurization of the balloon, and the step of releasing the graft fromthe casing includes selectively pressurizing the balloon within thecasing to rupture the casing substantially along perforations to releasethe graft from the casing.
 8. A method for reconstruction of aortictissue, using a sheathed graft encased in an inelastic casing with aloop element attached thereto, and a stabilizing catheter having aplurality of selectively deployable extensions at one end thereof, themethod comprising the steps of:introducing the sheathed graft through anintroduction site to position the sheathed graft at a proximal part ofthe aortic tissue by advancing the graft into position at the aortictissue via one femoral artery:releasing the graft from the perforatedcasing; introducing a guidewire through the loop element into thefemoral arteries and the iliac arteries; pulling a limb of the graftdown iliac arteries and femoral arteries opposite the introduction site;inserting a balloon occlusion catheter, having a selectively inflatableballoon, through the graft; selectively inflating the balloon to occludethe aorta; deploying the extensions of the stabilizing catheter at aproximal part of the graft to press the graft adjacent the aortic tissueto stabilize the graft at the aortic tissue; and securing the graft tothe aortic tissue.